var winWidth = 0;

var winHeight = 0;

function findDimensions() { // 函数：获取尺寸

	// 获取窗口宽度

	if (window.innerWidth) {

		winWidth = window.innerWidth;

	} else if ((document.body) && (document.body.clientWidth)) {

		winWidth = document.body.clientWidth;

	}

	// 获取窗口高度

	if (window.innerHeight) {

		winHeight = window.innerHeight;

	} else if ((document.body) && (document.body.clientHeight)) {

		winHeight = document.body.clientHeight;

	}

	// //通过深入Document内部对body进行检测，获取窗口大小

	// if (document.documentElement && document.documentElement.clientHeight &&
	// document.documentElement.clientWidth) {

	// winHeight = document.documentElement.clientHeight;

	// winWidth = document.documentElement.clientWidth;

	// }

	// 设置div的具体宽度=窗口的宽度的%

	if (document.getElementById("layout_main")) {
		winHeight = winHeight - 140;
		document.getElementById("layout_main").style.height = winHeight + "px";

	}

}